Reading multiple analog sensors

[charlesxiao96]

Hi, I'm trying to read 3 thermocouples, 3 heat flux sensors, and 1 solar flux sensor while also doing digital io. When I try to read the 7 sensors with the winDaq program, it gives no issues, but when I try to read them with my program the readings are unstable and erroneous. What's strange is that reading from ports 1 and 2 seem to be fine, but the other ports seem to be causing issues. Any insights on what the potential causes of this issue is?

[slightlynybbled]

Greetings -

I don't know exactly what the issue is. Could you post your setup code and I can try to replicate?

Thanks!

[charlesxiao96]

Thanks for the reply This code is basically the same as the example, but modified to read multiple sensors. Could it possibly be an issue with the packet size?

testtest2_2.txt

[slightlynybbled]

Charles -

Thank you for the code snippet. Your setup code is as follows:

channels = [
    AnalogPort(2, analog_range='0.025', filter='average', loglevel=loglevel),
    AnalogPort(4, analog_range='0.025', filter='average', loglevel=loglevel),
    AnalogPort(8, analog_range='0.025', filter='average', loglevel=loglevel),
    AnalogPort(1, thermocouple_type= 't',filter='average'),
    AnalogPort(3, thermocouple_type= 't',filter='average'), 
    AnalogPort(7, thermocouple_type= 't',filter='average')
]

I have noticed in the past that I need to set up the channels in numeric order. I'm not sure why yet, and I haven't investigated. Try this:

channels = [
    AnalogPort(1, thermocouple_type= 't',filter='average'),
    AnalogPort(2, analog_range='0.025', filter='average', loglevel=loglevel),
    AnalogPort(3, thermocouple_type= 't',filter='average'), 
    AnalogPort(4, analog_range='0.025', filter='average', loglevel=loglevel),
    AnalogPort(7, thermocouple_type= 't',filter='average'),
    AnalogPort(8, analog_range='0.025', filter='average', loglevel=loglevel),
]

If that has issues, maybe try assigning the thermocouples on 7 and 8 to 5 and 6? I have deployed code into production that uses 4 channels, but not 6.

I look forward to hearing from you,

j

[charlesxiao96]

Thank you. Setting the channels in numeric order appears to help. I'll keep you posted if other issues pop up